We use QCRs in the Comparagrid domain ontology. I think it's also the only way
to constrain what kinds of things participate in specific kinds of processes
using BFO. So, from the end-user perspective, they are a vital bit of
expressivity. The work-arround is to introduce syntactic sub-properties to
float the restrictions on, but then bad things happen when you try to infer
things because the property hierachy can't be closed off (covering
constraints on properties).
So I guess what I'm sudgesting is that you fix the RDF encoding of QCRs,
rather than removing this feature from owl 1.1.
Matthew
On Monday 17 December 2007, Jim Hendler wrote:
> I remind you all that the WG reopened the case of QCRs due to Alan
> Rector's comments. At that point we found no concrete syntaxfor
> which there was a consensus and we chose to POSTPONE the issue - I
> don't see that the situation has changed - if the OWL 1.0 WG felt
> that the DAML solution was appropriate we certainly would have chosen
> to add it when we reopened the issue. We didn't - and I don't see
> what has changed -- there's still very few users demanding it, and it
> still requires creating an arbitrarily ugly and confusing syntax.
> WHen I thought the OWL 1.1 syntax worked, I was happy with this, but
> now that it has been exposed to have troubles, I don't see going back
> to earlier solutions that were already rejected as a way out - seems
> to me work should go into fixing what is there, and if that is
> undoable, postpone again.
> -JH
>
> On Dec 17, 2007, at 3:24 AM, Peter F. Patel-Schneider wrote:
> > The resolution to not include QCRs in OWL had the following rationale
> > http://lists.w3.org/Archives/Public/www-webont-wg/2002Apr/0264.html
> > (numbering added):
> >
> > The qualified restrictions of DAML+OIL:
> > 1/ - have added to the difficulty of learning the language
> > 2/ - have not been used in practice
> > 3/ - are barely understood by the community
> > 4/ - potentially add to the difficulty of implementing the language
> > 5/ - have no compelling use cases
> >
> >
> > Since then there have been multiple calls for the expressive power of
> > QCRs, including the one by Alan Rector back in 2003, overturning at
> > least points 2 and 5. The use of QCRs at least partly overturns point
> > 3. Several implementations of QCRs exist in both UI tools (e.g.,
> > Protege 4)
> > and reasoners (e.g., Pellet), overturning point 4.
> >
> > I think that this is quite a significant change from the situation in
> > 2002.
> >
> > Peter F. Patel-Schneider
> > Bell Labs Research
> >
> > PS: For more information on QCRs in the WebOnt WG, see
> > http://www.w3.org/2001/sw/WebOnt/webont-issues.html#I3.2-Qualified-
> > Restrictions
> >
> >
> >
> > From: Jim Hendler <hendler@cs.rpi.edu>
> > Subject: Re: [OWLWG-COMMENT] Example why current RDF mapping for
> > QCRs might hurt OWL-1.1-Full [Re: PROPOSAL to close ISSUE-68]
> > Date: Sun, 16 Dec 2007 17:18:32 -0500
> >
> >> I have no objection to the solution that was used in OWL 1.0 for
> >> this. So far, if a feature adds problems to DL, we apparently throw
> >> it out immediately, but if it causes problems to full, we try to find
> >> a work around without worrying too much if it cases problems or
> >> confusion - I just fine this asymmetry to be troubling. So I propose
> >> we don't include QCRs, since the solution proposed is one that was
> >> already considered and rejected in OWL 1.0 - what has changed?
> >> -JH
>
> "If we knew what we were doing, it wouldn't be called research, would
> it?." - Albert Einstein
>
> Prof James Hendler http://www.cs.rpi.edu/~hendler
> Tetherless World Constellation Chair
> Computer Science Dept
> Rensselaer Polytechnic Institute, Troy NY 12180